Most users should not make changes to the default madVR settings, and the changes themselves can sometimes cause problems. DirectShow was one of our biggest support problems before Red October and the problems disappeared once we made the switch.
If there are settings that should be tweaked, please propose and discuss them.
The problem is that madVR's scaling settings range from Bilinear which is low quality, but will run perfectly well on integrated graphics, to Jinc scaling with an anti-ringing filter which can require a gaming-class GPU to run smoothly, and there's a big range in-between those two. When you are in the medium quality scaling options, you usually have to trade-off between sharpness and aliasing or ringing artifacts, and this is user preference more than anything else. (I prefer to sacrifice some sharpness to avoid ringing/aliasing)
Media Center's display mode switcher is not as advanced as the one in madVR, and does not account for things like film mode (where madVR can reclock a 25fps film to 24p) so you still have to enter the madVR config to set that.
There is also an upcoming feature to deband the image, which people may want to use, but it's not something I would want to leave enabled in a preset, as it depends on the quality of your source material.
I have not done a clean install of Media Center for a while so I'm unsure about what your madVR defaults are, but I think it would be useful to offer something in the way of presets for madVR - you could easily have five different levels of quality setting.
This might actually be the best way to handle it, as a "lowest" quality setting would be a good way for people to see if their system could even handle madVR at all, before trying the higher quality settings.
I'm happy to have a look over what the MC19 madVR defaults are and make some suggestions, or come up with five quality presets.